package com.szj.filter;

import com.szj.utils.CurrentHolder;
import com.szj.utils.JwtUtils;
import io.jsonwebtoken.Claims;
import jakarta.servlet.*;
import jakarta.servlet.annotation.WebFilter;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;

import java.io.IOException;

@Slf4j
@WebFilter(urlPatterns = "/*")
public class TokenFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //1.获取请求路径
        String requestURI = request.getRequestURI();// /emp/login

        //2.判断路径是否是登录路径
        if (requestURI.contains("/login")){
            log.info("登录请求，放行");
            filterChain.doFilter(request, response);
            return;
        }

        //3.获取请求头中的token
        String token = request.getHeader("token");

        //4.判断token是否存在，如果不存在，则返回错误信息(响应401状态码)
        if (token == null || token.isEmpty()){
            log.info("令牌为空，响应401");
            response.setStatus(401);
            return;
        }

        //5.如果存在，校验token，如果校验失败，则返回错误信息(响应401状态码)
        try {
            Claims claims = JwtUtils.parseJWT(token);
            Integer empId = Integer.valueOf(claims.get("id").toString());//claims.get("id")返回的是Object类型，所以后续还需要进行类型转换
            CurrentHolder.setCurrentId(empId);//存入

            log.info("当前登录员工ID：{},将其存入ThreadLocal", empId);
        } catch (Exception e) {
            log.info("令牌非法，响应401");
            response.setStatus(401);
            return;
        }

        //6.如果校验成功，则放行
        log.info("令牌合法，放行");
        filterChain.doFilter(request, response);

        //7.删除ThreadLocal中的数据
        CurrentHolder.remove();
    }
}
